In many applicational areas, perfumes are used for masking malodors. Annoyance caused by malodors occurs frequently in daily life and impairs personal well-being. Such malodors are, for example, those resulting from substances transpired or excreted by humans, in particular, perspiration, mouth odors, feces and urine, odors caused by animal feces or urine, in particular, those of domestic pets, kitchen odors, such as those resulting from the preparation of onions, garlic, cabbage or fish, odors due to tobacco smoke, garbage, bathrooms, molds and waste.
In addition, malodors may be caused by many industrially produced basic materials used in cleansing agents, such as, for example, detergents and fabric softeners, or in body care products, such as, for example, soaps and cosmetics. The use of specific cosmetic preparations, such as, for example, hair dyes, hair-forming agents and depilatories, also produce malodors.
Many rubber and plastic products also produce malodors if, due to the method of their manufacture, they still contain quantities of highly odorous, volatile active ingredients. These malodors are usually caused by particularly odorous substances which are, however, generally only present in trace amounts. Such substances include, for example, nitrogen-containing compounds such as ammonia and amines, heterocyclic compounds such as pyridines, pyrazines, indoles, etc., and sulfur-containing compounds such as hydrogen sulfide, mercaptans, sulfides, etc.
The masking of malodors is a problem which is difficult to handle and solve with perfume compositions. Usually, it is only possible to mask malodors by means of a specially developed perfume oil having specific types of fragrances.
Malodor counteracting compositions are particularly advantageous when they are capable of reducing the intensity of malodors without themselves possessing any significantly intense odor or fragrance. Such active ingredients do not mask malodors; rather, they neutralize the malodors. This has the advantage that, when using such active ingredients for perfuming objects or products having malodors, perfume oils of any desired type of fragrance can be used. The consumer can, therefore, be offered a considerably broader range of fragrance types for combating malodors.
In addition, active ingredients which neutralize malodors, provide the possibility of reducing the quantity of perfume oil previously required for masking odors. It is also possible to use less intensely odorous perfumes for combating malodors than those heretofore employed.
Another area in which malodor reducing compositions find utility is in breath freshening compositions such as chewing gum, mints, mouthwashes, lozenges and sprays. In addition to flavoring and perfuming ingredients which mask oral malodors, it is also useful to neutralize the ingredients which cause such malodors.
In recent years, a wide variety of substances have been proposed for use in neutralizing malodors, including some substances traditionally used as perfumes and/or as ingredients in deodorizing compositions. Bornyl acetate and isobornyl acetate are well-known perfuming ingredients and have been used in deodorizing compositions and to lend a pleasing scent to various types of consumer products. Examples of such uses are shown in U.S. Pat. Nos. 5,198,144, 5,451,346, 5,554,588, 6,019,855 and 7,569,232 and in Patent Application Publication US 2006/0228250. More recently, the use of bornyl acetate and isobornyl acetate, separately and together, has been disclosed in Patent Application Publications US 2008/0207481 and US 2008/0221003, as ingredients in compositions intended to exhibit varying discernable odors.
It has now been discovered that, although bornyl acetate and isobornyl acetate have some odor-neutralizing effect and can be considered as malodor counteractants, combinations of bornyl or isobornyl acetate with certain low molecular weight monocarboxylic acids have shown surprising enhanced effectiveness in neutralizing malodors. Although the acids themselves may possess a characteristic odor, in combination with bornyl acetate or isobornyl acetate they act as agents to neutralize malodors.